Pulp dewatering apparatus



Jan. 18, 1966 A. c. BERGES PULP BEWATERING APPARATUS 7 Sheets-Sheet 1Filed May 21, 1963 Jan. 18, 1966 A. c. BERGES PULP DEWATERING APPARATUS7 Sheets-Sheet 2 Filed May 21, 1963 w mo Jan. 18, 1966 A. c. BERGES 3,

PULP DEWATERING APPARATUS Filed May 21, 1963 '7 Sheets-Sheet 3 5/ 62 6/22 6/ g {4 x A 1 g\ g LY. 52 45 l V t l i 45 1a Iv ue'moa Jan. 18, 1966A. c. BERGES 3,230,138

PULP DEWATERING APPARATUS Filed May 21, 1963 7 Sheets-Sheet 4.

in vewm E i! wm Jan. 18, 1966 A. c. BERGES PULP DEWATERING APPARATUS '7Sheets-Sheet 5 Filed May 21, 1963 Jan. 18, 1966 A. c. BERGES PULPDEWATERING APPARATUS 7 Sheets-Sheet '7 Filed May 21, 1963 K L Q UnitedStates Patent 3,230,138 PULP DEWATERING APPARATUS Andre Charles Berges,Lorp par St.-Lizier, Ariege, France Filed May 21, I963, Ser. No. 282,669Claims priority, application France, .Iune 6, 1962, 899,926 7 Claims.(Cl. 162-307) This invention relates to pulp processing apparatus of thetype used to remove part of the liquid content in :pulps of fibre andsimilar wet divided materials, and is especially though not exclusivelydirected to paper making apparatus.

In the manufacture of paper and similar fibre pulp products, a wet pulpof comparatively high water content is delivered on to one end of anendless wire cloth which is continuously advanced over an underlyingflat surface, which is provided with spaced slots or apertures throughwhich suction is applied to the under surface of the Wire cloth so as todraw out part of the liquid from the pulp as it progresses towards thedelivery end of the machine. In Fourdrinier machines used in the paperindustry and embodying the above operating principle, a so-called wetpress is frequently mounted beyond the delivery end of the wire cloth,said press usually including an endless movable felt adapted to receivethe partly dried pulp from the wire cloth, and a pair of press rolls orcylinders engaging the upper and lower surfaces of said felt to wringfurther liquid out of the pulp, and simultaneously flatten the pulpfibres. Sometimes suction is also applied at the wet press to furtherthese operations.

Objects of this invention are, broadly, to provide a number ofimprovements in pulp processing apparatus of the kind just outlined.Specific objects are to provide improved drying means, involving thejoint actions of compression and suction, whereby the ultimate drynessof the pulp issuing from the wire cloth can be brought to a pointsubstantially higher than was heretofore generally possible; to providerolls in the suction chambers of such apparatus for engagement with theunder surface of the wire cloth, and improved supporting means for suchrolls whereby their pressure engagement with the wire can be moreeffectively controlled; to provide improved pulp drying apparatusoperable to impart a higher degree of dryness to pulp fed theretowithout increasing the general dimensions of the apparatus;simultaneously to facilitate the effective recovery of the valuable orharmful liquid constituents of the pulp to permit recovery ordestruction, respectively, of such constituents; to provide in suchapparatus combined suction and compression drying means as singleseparate units, readily insertable and with drawable into and from theframe of the apparatus from a side thereof; to provide such drying meansin which the degree of pressure applied to the pulp will be more closelyand easily controllable; to provide such drying means including drierrolls that can be made to extend the full width of the wire clothwithout having to be enlarged or made convex in their mid-regions; toprovide apparatus of the type specified above having improved provisionfor easy removal and replacement of the wire cloth. Other objects relateto the provision of improved wet presses, especially wet suctionpresses, for use with pulp drying apparatus of the general classreferred to.

Exemplary embodiments of the invention will now be described in detailfor purposes of illustration but not of limitation and with reference tothe accompanying drawings, wherein:

FIGURE 1 is a side elevational view of a Fourdrinier machine embodyingimportant teachings of the invention.

3,230,138 Patented Jan. 18, 1966 ice FIGURE 2 is a horizontal section online IIII of FIGURE 1.

FIGURE 3 is a transverse section on line III-III of FIGURE 1.

FIGURE 4 is an end view of the machine on the line of view indicated bythe arrow F in FIGURE 1.

FIGURE 5 is a vertical section on line V-V of FIGURE 2, but on anenlarged scale.

FIGURE 6 is a transverse section on line VI-VI of FIGURE 5.

FIGURE 7 is a detailed view in vertical section of one of the suctionboxes, on a further enlarged scale.

FIGURE 8 is a horizontal section on the line VIIIVII of FIGURE 7.

FIGURE 9 is a further horizontal sectional view, on the line IXIX ofFIGURE 7.

FIGURE 10 is a fragmentary view similar to FIG- URE 7 but relating to amodification in detail.

FIGURE 11 is a view illustrating the delivery end of a Fourdriniermachine which may be similar to the one generally shown in FIGURE 1 andfollowing, but including a wet press according to a further feature ofthe invention.

FIGURE 12 is a horizontal section on line XIIXII of FIGURE 11.

FIGURE 13 is a fragmentary view in section on the line XIl1XIII ofFIGURE 11, illustrating a detail on an enlarged scale.

FIGURE 14 is a view illustrating the end part of an improved wet pressin elevation, with parts in section.

FIGURE 15 is a transverse section on the line XV-XV of FIGURE 13.

FIGURE 16 is a partial front view showing the end of the wet press asshown in FIGURE 14.

FIGURES 1'7 and 18 are partial sectional views on the lines XVII-XVIIand XVIII-XVIII of FIGURE 14, respectively.

The paper making machine illustrated comprises a main frame includingupper and lower side members 1a, uprights 1b and cross members 1c in theform of suitably interassernbled channel sections in the presentexample. The main frame is pivoted at its rear end about about atransverse pivot axis 2 on a pair of brackets 3 upstanding from thefloor. Secured to the under side of the frame in a central part of it isa fiat under-frame or base 4 made of interassembled sectional membersand projecting laterally beyond one side of the main frame as shown at4a in FIGURES 2, 3 and 4. The front part of the under-frame 4, 4a restsupon a suitable transverse support or cradle 5 in such a manner that themain frame of the machine is supported in an upwardly forwardly slantingposition as is apparent from FIGURE 1. The angle of slope can beadjusted depending on the nature of the pulp to be treated, as bysubstituting for the cradle 5 another cradle of different height orinterposing shims or spacer blocks between the cradle and theunder-frame.

Secured to the upper part of the laterally projecting sub-frame part 4ain longitudinally spaced relation are uprights or arms 5 that serve tosupport within the main frame 1, in cantilever relation to said arms, aninner frame presently described, which contains a number of suctionboxes disposed in a row lengthwise of the path of the pulp through themachine. The suction hoses are four in the illustrated example and areshown at 7, 8, 9 and 10 in FIGURES 1 to 5. The upper surfaces of saidsuction boxes define a continuous table or wire frame. The inner framecontaining the suction boxes includes the lower and upper side members13 and 14 respectively, and cross members or bulkheads 12, 12a and 12bwhich constitute extensions of the supporting arms which as shown inFIGURES 5 and 6 are bent inwards at their upper ends and extend thewidth of the inner frame. The lower side members 13 extend the fulllength of the row of suction boxes 7, 8, 9 and 10 (FIGURES 1 and whereasthe upper side members 14 are limited in length to that of the lastthree boxes 8, 9 and 10.

The upper side members 14 are assembled to the cross members orbulkheads 12 by means of screws 15 some of which engage threaded holesformed in bosses 16 projecting from the cross members 12 while othersare similarly connected to a bracket 17 projecting from one of the crossmembers 12, and yet other screws 15 connect with a box 118 secured tothe end cross member 12b. The lower side members 13 of the inner frameare welded to the end cross members 12a and 12b and are furtherconnected rigidly by way of angle members 18 to the intermediate crossmembers 12.

The inner frame thus supported in cantilever relation from the arms 6has its longitudinal sides opened throughout their vertical extent anddivided longitudinally by the bulkheads or cross members 12.

Supported from the end bulkheads 12a and 12b beyond the ends of theinner frame are bearings 19a and 19b respectively in which horizontalshafts 20a, 20b are journalled. Secured on the shafts 20a and 20b aredrums 21a, 21b which serve as means for supporting and driving anendless wire cloth 22. Tension rollers 23a, 23b are suitably supportedfor engagement with intermediate points of the lower run of the wirecloth 22. The bulkheads 12 are suitably cut out as at 120 (FIGURE 6) topermit the wire 22 to pass through them.

As will be described later, the drums 21a, 21b are rotated in operationto drive the wire 22 in the direction indicated at f1.

The first suction box 7 traversed in the direction of travel f1 of thewire cloth 22 comprises a pair of channels 24a, 24b (FIGURE 5) equal inlength to the angles 18 as shown in FIGURE 6. The channels 24a, 24bextend the full width of the inner frame from the front lower sidemember 13a to the rear lower member 13b. The channels 24a and 24b havetheir lower flanges assembled to the ends of a plate 25 and their upperflanges secured to a plate 26 the upper surface of which is flush withthe lower surfaces of the upper side members 14 (FIGURES 5 and 6). Saidplate 26 is formed with a series of transversely extending slots 27extending over a length somewhat less than the width of the wire cloth23 (FIGURE 2), so that the side margins of the wire cloth tightly engagethe upper surface of plate 26 beyond the ends of the slots 27.

The suction box 7 has its front side i.e. the side adjacent side member13a, sealed by a panel 28 formed with an inspection hole 29 normallysealed with a cover 30 provided with latching means31. On the oppositeside, adjacent frame side member 13b, the box 7 is sealed by a panel 32formed with an opening 33 over which is secured a suction nozzle 33aconnectable with a source of suction. Secured to the upper wall of box 7and depending therefrom are partial upper partitions 34, positionedbetween the adjacent slots 27 in the plate 26 over which the wire 22slides. The suction box 7 is blocked in position in the inner frame bybeing tightly fitted between the cross members or bulkheads 12a and 12(FIGURE 5).

The suction box 8 which follows box 7 in the direction of pulp travelcomprises two channels 35a and 35b also equal in length to the angles18. The channels 35a and 35b have their lower flanges interconnected bya plate 36 and their upper flanges interconnected by a plate 37 formedwith a central opening somewhat shorter than the width of the wire 22(FIGURES 2 and 5) as was the case for the slots 27. A support 39 havingits ends secured to the respective channels 35a, 35b supports a set ofthree rolls 40 freely rotatable about spaced transverse axes,constituting a cradle on which are supported a further pair of freelyrotatable rolls or cylinders 41, the upper parts of which are positionedwithin the opening 38 so as to engage the under surface of wire 22. Thecylinders 40 and 41 are equal in length to the width of the opening 38.The suction box 8 has its front side, adjacent frame member 13a, sealedby a panel 42 and its opposite side sealed by a panel 43 formed with anopening 44 over which is attached a suction nozzle 44a connected with avacuum source. The box 8 is held in position within the inner frame bymeans of screws 45 extending upwards through the side members 13 andapplying the upper plate 37 of the box into engagement with the underface of the upper side members 14.

The third suction box 9 comprises a pair of channel members 46a and 46b,an under plate 47 and an upper plate 48 assembled thereto, said upperplate having an aperture 49 also a little shorter than the width of thewire 22. The box is sealed on the front side 13a by a panel 50 and onthe opposite side by a panel 51 having an opening 52 surrounded by asuction nozzle 52a connected with a vacuum source. The box is held inposition within the inner frame with screws 45 similarly to box 8,

The fourth suction box 10 is generally constructed and mounted in asimilar manner to box 9, and corresponding parts have been designatedwith the same references.

The internal arrangement of each of the suction boxes 9 and 10 isillustrated in FIGURES 7, 8, and 9 and in FIGURE 3. As there shown, thechannels 46a and 46b are interconnected within each box by braces 53connected thereto by brackets 53a, and are further interconnectedthrough three partition plates 54 and 54b secured thereto throughflanges 54a. The plates 54, 54b serve to support a shaft 55 extendinglongitudinally of the box and blocked in position by means of nuts 55aengaging the end plates 54b. In each of the two spaces defined betweenthe central plate 54 each of the end plates 54b are mounted flanges 56,one pair in each said space. The said flanges are mounted for freepivotal movement about the shaft 55 and each pair of them is connectedat one side to a plate 56a engaging an elastic diaphragm 57 defining oneend wall of a casing 58, the opposite end wall of which is formed byparts of the channel 46b; secured to said channel, within the casing, isa block 59 herein made of wood. A conduit 60 opens into the casing 58and is outwardly connected to a source of pressure fluid, e.g.compressed air, whereby force can be applied to the diaphragm 57 torotate the flanges 56 in an upward direction about shaft 55.

The flanges 56 are formed with cutouts in which are supported two shaftson which are secured rolls 61, there being one roll between the flanges56 of each pair. The rolls 61 are disposed in a pair of parallel rows,forming a cradle on which is supported a roll 62 having convex ends 62aabutted against plates 63 from which project set screws 64 extendingthrough the braces or spacers 53. The rolls 62 are disposed within theopenings 49 and are equal in length with the latter, and are inengagement with the under face of the wire cloth 22 the upper face ofwhich engages the larger-diameter press rolls 65, there being one pressroll provided for each of the boxes 9 and 10. Each press roll ispreferably provided around its periphery with a rubber or equivalentlining 66, and is secured on a shaft 67 driven through suitable means inthe direction indicated by arrow f2. The shafts 67 (also see FIGURE 5)are carried on arms 68 pivoted at 69 (see FIGURE 1) in bearings 70secured to the underside of the upper side member 1a of the main frame.The arms 68 are adjustable in position by means of screws 71 operatedfrom handwheels 72.

As a modification of the construction described, the roll 62 cradled onthe rows of rollers 61 within the boxes 9 and 10 may, as illustrated inFIGURE 10, be replaced by a hollow roll 73 having perforations 74 in itsside wall.

A casing 118 (see FIGURE 5) secured to the forward end cross member 12bis internally connected to a source of pressure fluid, e.g. the samesource of compressed air as that to which the casings 58 are connected.

The upper surface 118:: of casing 118 (FIGURE 5) is in engagement withthe under face of the wire cloth 22 and is formed with a set ofperforations 118b.

The main frame 1 has secured to its rear extremity, as referred to thedirection f1 of travel of wire 22, projecting brackets 75 (see FIGURES1, 2 and 4) serving to support trunnions 76 projecting from the sides ofa supply or feeder casing 77 into which the pulp to be treated isdelivered. The feeder casing 77 is internally provided with four pairsof partition walls 78a, 78b between the front wall 77a and rear wall 77bthereof, dividing said easing into upwardly flared passageways. Se curedto the front wall 77a are four tubes 79 which open in between thepartitions 78a, 78b of each pair. The tubes 79 extend from a manifold 80to which pulp is supplied by way of a conduit 81.

The casing 77 is followed by a feeder passage or channel defined byplates 82 to 87, and extending along a sinuous path. This passageincludes a lower generally horizontal plate 84 secured to and extendingfrom a point of the front Wall 7712 of feeder 77 somewhat below its top,an upper generally horizontal plate extending from the top of the rearwall 77:: and spaced above plate 84 to define therewith a horizontalpassage section, a plate 85 attached to the front end of lower plate 84and extending upwardly from it, and a plate 82 attached to the front endof upper plate 83 and extending upwardly from it to define with plate 85a vertical passage section. Further, the passage includes a plate 86attached to the upper end of plate 85 and extending forwardly from it,and a plate 87 spaced above plate 86 to define with it a forwardlyextending passage section. The front end of plate 86 lies flush with theupper surface of the wire 22 at the point where said wire is supportedby the drum 21a. The upper plate 87 rather than being attached at itsrear end to the plate 82 is mounted for vertical adjustment by means ofbolts 88 (see FIGURE 5) positionable in vertical slots 89 formed in sideflanges of the plate 87.

The side walls 77 of the feeder box or hopper extend up to the level ofthe rear end of the lower plate 86. Extending beyond each of these sidewalls in the same plane as it is one side run 90a of a related endlessbelt 90 trained around pulleys 91 supported on a frame 92 secured to theside walls of the hopper. The endless belts 90 are engaged by tensionrollers 93 biassed by springs 94 urging the two sides or runs of eachbelt 90 toward each other. The belts 91 are driven at a linear velocityequal to that of the wire cloth 22 in the same direction (f1) as it andserve as means for confining the pulp issuing from the hopper within thewidth dimension of the wire 22.

Projecting from the top of plate 82 is a bracket 95 to which is pivoteda :clevis 96 from which extends a screw rod 97 extending through a guidebushing 98 pivoted on a transverse axis from a fixed bracket 99.Threaded on the screw rod 97 is a nut 100 to which is secured ahandwheel 109a. Manual rotation of the handwheel to displace the screwrod 97 axially eg in the direction f3 (FIGURE 1) will rotate the feedertogethetr with the belts 90 bodily around the trunnions 76 relatively tothe brackets 75. This action serves to move the plate 86 and belts 90away from the wire 22 for servicing especially for the purpose ofreplacing the wire when desired.

The apparatus as so far described operates as follows. The aqueous pulpof fibre material is delivered to the base of feeder 77 through the pipe81 (FIGURES 1 and 4) manifold 80 and inlet tubes 79 and rises up theflaring passageways defined between the partitions 78a, 78]), thenpasses into the sinuous passage defined by the plates 82 to 87, in whichany turbulence present in the stream of pulp subsides owing to thesinuous nature of the passage and quiescent flow conditions are impartedto the stream. The pulp spreads over the surface of wire cloth 22 toform a sheet laterally confined by the belts 9b which accompany the wirein its slowly rising path of advance. The liquid is drawn out of thepulp through the Wire 22 by the suction present in the sequence ofsuction boxes. In the last two suction boxes of the series the action ofthe vacuum combines with that of the press rolls 62, 65. Beyond the lastsuction box 10 the drained pulp is subjected to the action of compressedair jets issuing from the casing 118 and serving to detach the pulp fromthe wire. The sheet of pulp is then collected in any suitable way e.g.in a pit, not shown, located under the end drum 21b One typicalapplication of the above described apparatus is to the production ofkraft pulp by the sulphate process. The cellulose fibre at the outletfrom the digesters is suspended at a concentration in the range of from5 to 10% in an aqueous medium rich in valuable constituents known asblack liquor. This black liquor is desirably collected both for therecovery of valuable inorganic salts therefrom and to extract organicconstituents also for recovery and/or for burning them in order to avoidpolluting the river waters used for disposal.

In this application the main frame of the apparatus may be mounted at aninclination to the horizontal plane providing a slope of about 10% forthe wire, and the wire may be driven at a linear velocity within therange of from 15 to 35 meters per minute. The suction pumps or fansserving as sources of vacuum are controlled to provide increasingly highdegrees of suction in the se quence of suction boxes, one suitablepattern being from 50 to cm. water in suction box 7, from 120 to 150 cm.water in box 8, and from 250 to 400 cm. water in each of the final boxes9 and 10. The rolls 62, 65 are adjusted to apply to the pulp in the box9 a pressure of from 10 to 15 kg. per linear centimeter, and in box 10 apressure of from 15 to 25 kg. per linear cm. The rolls 65 are linedperipherally with a coating of rubber having a hardness number of from70 to Shore.

By this procedure a kraft pulp weighing about 1000 grams per squaremeter can be obtained with a dryness of from 30 to 35%. Such a degree ofdryness represents a considerable advance over what is obtainable wtihpriorart apparatus with which dryness degrees of about 15% were all thatcould be obtained. In practice, a series of apparatus units similar tothe one described can advantageously be used, with the drained pulpbeing replaced in suspension between successive units, wherebysubstantially all of the black liquor content of the pulp can beextracted.

According to an important feature of the invention, the frame of theFourdrinier machine is adapted to have a wet press mounted thereon, saidwet press generally comprising a pair of rolls mounted one above theother and having an endless belt or felt fed between them. The pulpsheet from the Fourdrinier is picked up by the felt and fed therebybetween the two rolls to be thereby subjected to a controlled pressurefor draining the pulp, the water draining out through the felt ahead ofthe lower roll and being discharged. The pressure rolls or cylinders areadvantageously mounted in a manner similar to that described withreference to FIGURES 7 to 10 in connection with the suction boxes 9 and10 of the Fourdrinier.

As described each of the lower rolls 62 (or 73) is supported on a cradleformed by a row of rollers 61 whereby the vertical position of the roll62 (or 73) can be adjusted through suitable pneumatic actuator means asdescribed. Similar advantages can be derived if the Wet press used isconstructed according to the modified embodiment now to be describedwith reference to FIG- URES 11 to 18.

As shown in FIGURES 11 and 12 each of the upper side members In of themain frame has a channel extending from its forward end at a downwardangle to provide an auxiliary end frame for supporting rolls 121 overwhich an endless belt or felt 122 of a wet press is trained. Projectingupwards from the lower side members 1a are L-shaped brackets 123 to theupper ends of which are pivoted crank levers 124, 129. The generallyhorizontal arms 124 of the crank levers are arranged to provide bearingsfor a shaft on which is mounted a cylinder 125 forming the upper roll ofthe wet press and having a length at least equal to the width of theFourdrinier. The lower cylinder of the wet press is provided by a hollowroll 126 having a perforate wall, and described more in detail presentlywith reference to FIGURES 13 to 18. The cylinder 126 is equal in lengthtocylinder 125 and is supported at its ends in bearings supported onbase supports 127 projecting up from the lower arms of the L-brackets123. An endless belt or felt 122 is supported as later described so thatits upper run extends between the cylinders 125 and 126. The width ofthe gap between the cylinders is adjustable by means of set screws 128engaging threaded holes in the upstanding legs of the brackets 123 andhaving their tips engaging the depending legs 129 of the crank levers124-129. Further, a screw rod 130 is threaded through a nut pivoted on alug projecting from a side of the upright bracket arm 123 and has apoint pivotally attached to the lower end of the depending arm 129.Rotation of the screws 130 makes it possible to raise the upper cylinder125 when required to service or replace the felt 122. In the normaloperating condition the screws 130 keep the arms 129 applied inengagement with the ends of screws 128.

Referring now to FIGURES 13 to 18, it will be seen that within theperforate hollow cylinder 126 there extends a pair of longitudinalchannels 131 disposed with their flanges directed outwardly and havingtheir lower flanges interconnected by a flat web 132. The sectionalassembly 131-132 is greater in length than the cylinder 126, and itsends projecting beyond the ends of the cylinder are secured to theaforementioned base supports 127. Secured to the upper surfaces of theupper flanges of channels 131 are the horizontal flanges or angles 133each having a small channel 134 secured to the top of the inner surfaceof its vertical flange. Sealing strips 135 are inserted into the smallchannels 134 and project upwards therefrom into engagement with theinner surface of cylinder 126 to define a sealed enclosure of generallyrectangular cross section extending the full length of cylinder 126. Thechannels 131 are interconnected at points spaced along them by spacers131a each formed with a central bushing 135 through which a short rod136 is slidably positioned. Each rod 136 has a bracket 137 secured toits upper end, said bracket having spaced upstanding flanges serving tojournal in parallel spaced relation the pivot pins of a pair of rollers138. The rods 136 each have a plate 139 secured to its lower end andresting on an elastic diaphragm 140 extending across the width of theweb 132 while being maintained spaced above said web so as to definewith the latter a flat chamber which is connected by way of a conduit141 with a source of pressure air.

Resting freely on the rollers 138 is a roll 142 the uppermost generatrixof which is held in resilient engagement with the inner surface ofcylinder 126. Thus it will be seen that in this embodiment as in the onedescribed with reference to FIGURES 7 to 10, the roll is supported inaccordance with the invention on cradling means that are verticallymovable.

The roll 142 is driven in rotation in the direction f4 by way of asuitable drive transmission 143 (FIGURE 12) connecting with one end ofthe roll. Hence the perforate cylinder 126 will be positively driven inthe same direction f4 about its axis. The upper cylinder 125 is mountedfor idle rotation about its axis. Consequently the felt 122 will act tofeed the sheet of pulp 22 in the direction 1. The cylinder 126 is guidedin its rotation by a first set of rollers 144 engaging its inner surfacejournalled on horizontal longitudinal axes in opposed pairs .beingsupported from the respective channel members 131 at spaced points alongthe cylinder, and a second set of single rollers 145 also supported forrotation from the channels 131 intermediate the paired rollers 144. Allsaid rollers are supported in flanges such as 146 mounted across theside flanges of each channel member 131. A small-diameter roll 147 equalin length to the cylinder 126 rests under its own weight on the innerwall surface of the cylinder at the lowermost point thereof, beingguided at its ends for free vertical movement in slotted plates 147adepending from the web 132. The axial positioning of the cylinder 126 iseffected by rollers 148 (FIGURE 12) supported for rotation abouttransverse axes in engagement with each of the end surfaces of thecylinder 126. Desirably the end portions of the cylinder 126 areprovided with suitable reinforcing hoops, not shown.

Extending through the cylinder 126 near its bottom is a pipe 149externally connected to a source of water under pressure, and havingspaced perforations in its walls for at all times discharging jets ofwater and/or cleaning agent against the inner wall surface of cylinder126 to prevent clogging in the perforations thereof. The waterdischarged from the cylinder 126 is collected in a trough 150 underlyingthe cylinder and is disposed of.

As earlier noted the channels 131, web 132, angles 133 and sealingstrips 135 define an inner sealed enclosure in the cylinder and thisenclosure is connected through suitable means to a source of suction.The suction generated in this enclosure adjacent the surface of the pulpsheet moving past the presser cylinders enhances the draining of thepulp and the water drained off is discharged from the end of saidenclosure by means not shown. A sprayer pipe 151 (FIGURE ll) ispreferably provided to spray pressure water against the inner surface ofthe felt to keep the felt free of fibre fragments ten-ding to cling tothe outer surface of the felt.

A pair of small presser rolls 152 is further provided to act on theopposite sides of the felt ahead of the outlet end of the Fourdrinier todrain the felt free from excess liquid.

It will be understood that a great many modifications may be introducedinto the embodiments of the invention illustrated and described withoutexceeding the scope of the invention. Various of the features disclosedmay be applicable in various combinations independently of otherfeatures. The number and design of the suction boxes in the Fourdriniershown can be varied from what is illustrated especially in FIGURES 1 and3, although preferably the general arrangement shown, wherein the upperpresser rolls 65 are combined with the lower rolls 6-2 only in one, twoor more of the end suction chambers of the sequence provide, isretained. Certain suction boxes or chambers of the sequence, especiallythose at the supply end of the wire cloth, can be provided as ordinarysuction chambers, without the improved rolls of the invention.

What I claim is:

1. A fibre pulp processing machine comprising in combination a mainframe; supporting drum means mounted adjacent opposite longitudinal endsof said frame for rotation about transverse axes; an endless wire clothtrained about said drum means and having an upper surface arranged tosupport wet pulp thereon; means for rotating the drum means to advancesaid wire cloth with said frame defining a sequence of suction chambersdistributed longitudinally underneath said surface of the wire cloth;said suction chambers having upper walls underlying said cloth andtransversely elongated apertures in said walls; rolls positioned in saidchambers transversely thereto having upper portions extending throughsaid apertures into engagement with the under surface of said cloth;supporting means for said rolls in said chambers including cradlingmeans engaging lower portions of the rolls to permit rotation thereofand means for resiliently biassing the cradling means upwards to urgethe rolls into engagement with said cloth, including means for adjustingthe vertical elevation of said cradling means; and an inner frame, meanssupporting said inner frame within said main frame, means mounting saidsupporting drum means from opposite ends of said inner frame, said endless cloth being trained around said inner frame, and means forremovably supporting said suction chamber means in said inner frame forremoval therefrom and insertion thereinto through a side of said innerframe.

2. The machine claimed in claim 1, having a blower casing supported froma delivery end of said inner frame and positioned to blow compressed airagainst the under surface of said wire cloth and means connecting theblower casing to a source of compressed air.

3. The machine claimed in claim 1, wherein said means supporting theinner frame comprise longitudinally spaced supports extending from acommon side of said main frame and projecting into said main frame andmeans supporting the inner frame from said arms in cantilever fashion,and said suction chamber means are mounted in said inner frame forremoval and insertion through the opposite side of said inner frame andsaid main frame.

4. In fibre pulp processing apparatus, a wet suction press assemblycomprising a frame, endless felt means movably supported from said frameand arranged to receive pulp on an upper surface thereof, a hollow andperforate lower press roll and an upper press roll supported from saidframe for engagement with respective opposite surfaces of the felt meanson substantially coincident lines, the supporting means for said lowerpress roll including a generally horizontal frame member extendingthrough the hollow in the lower roll and having projecting ends securedto the frame, said frame member having a cavity defined therein, aplurality of rollers rotatably supported from said frame member withinsaid hollow and engaging spaced points of the inner periphery of saidlower press roll for guiding same in rotation, the cavity in saidhorizontal frame member being upwardly open to communicate with an upperportion of the inner wall periphery of said perforate lower roll, sealmeans on said horizontal frame member engaging said inner wall peripheryof the lower roll around the walls of said cavity, means participatingwith said seal means to seal said cavity except for the perforations insaid lower roll, and suction means connected with said cavity fordrawing off a liquid constituent through said perforations and felt fromsaid pulp.

5. The wet suction press claimed in claim 4, including an inner rollmounted for rotation within said cavity of the horizontal frame memberabout an axis parallel to that of said roll and engageable with an upperportion of said inner peripheral wall of the lower press roll, means insaid cavity :for cradlingly engaging an under portion of said innerroll, to support same for rotation, and means for resiliently biassingsaid cradling means upward including means for adjusting the elevationthereof.

6. The wet suction press claimed in claim 4, including an inner rollmounted for rotation within said cavity of the horizontal frame memberabout an axis parallel to the axes of said rolls and engageable with anupper portion of said inner peripheral Wall of the lower press roll,rollers in said cavity mounted for rotation about spaced axes parallelto said first mentioned axes and cradlingly engaging an under portion ofsaid inner roll to support same for rotation, means supporting saidrollers from said frame member, and fiuid pressure actuator meansconnected to said roller-supporting means for resiliently biassing saidrollers upward and for adjusting the elevation thereof.

7. The wet suction press claimed in claim 6, wherein said rollersupporting means comprise a support, means for pivoting said rollersabout said spaced axes at the top of said support, means defining asealed pressure chamber in the bottom of said cavity including aflexible diaphragm defining the top of said pressure chamber andengaging the base of said support, and means connecting said pressurechamber to a source of controllable air pressure.

References Cited by the Examiner UNITED STATES PATENTS 1,853,625 4/ 1932Lapeyrouse '162--350 2,270,465 1/ 1942 Nash 1623 14 2,950,507 8/1960Keyser. 3,035,512 5/1962 Beachler 17O 3,084,740 4/ 1963 Carrel 162-37 3FOREIGN PATENTS 546,471 9/ 1957 Canada. 1,018,583 10/1952 France.

889,244 2/ 1962 Great Britain.

OTHER REFERENCES Pickartz, German application No. R 14,124, publishedFebruary 1956.

DONALL H. SYLVESTER, Primary Examiner.

J. H. NEWSOME, Assistant Examiner.

1. A FIBRE PULP PROCESSING MACHINE COMPRISING IN COMBINATION A MAINFRAME; SUPPORTING DRUM MEANS MOUNTED ADJACENT OPPOSITE LONGITUDINAL ENDSOF SAID FRAME FOR ROTATION ABOUT TRANSVERSE AXES; AN ENDLESS WIRE CLOTHTRAINED ABOUT SAID DURM MEANS AND HAVING AN UPPER SURFACE ARRANGED TOSUPPORT WET PULP THEREON; MEANS FOR RATATING THE DRUM MEANS TO ADVANCESAID WIRE CLOTH WITH SAID FRAME DEFINING A SEQUENCE OF SUCTION CHAMBERSDISTRIBUTED LONGITUDINALLY UNDERNEATH SAID SURFACE OF THE WIRE CLOTH;SAID SUCTION CHAMBERS HAVING UPPER WALLS UNDERLYING SAID CLOTH ANDTRANSVERSELY ELONGATED APERTURES IN SAID WALLS; ROLLS POSITIONED IN SAIDCHAMBERS TRANSVERSELY THERETO HAVING UPPER PORTIONS EXTENDING THROUGHSAID APERTURES INTO ENGAGEMENT WITH THE UNDER SURFACE OF SAID CLOTH;SUPPORTING MEANS FOR SAID ROLLS IN SAID CHAMBERS INCLUDING CRADLINGMEANS ENGAGING LOWER PORTIONS OF THE ROLLS TO PERMIT ROTATION THEREOFAND MEANS FOR RESILIENTLY BIASSING THE CRADLING MEANS UPWARDS TO URGETHE ROLLS INTO ENGAGEMENT WITH SAID CLOTH, INCLUDING MEANS FOR ADJUSTINGTHE VERTICAL ELEVATION OF SAID CRADLING MEANS; AND AN INNER FRAME, MEANSSUPPORTING SAID INNER FRAME WITHIN SAID MAIN FRAME, MEANS MOUNTING SAIDSUPPORTING DRUM MEANS FROM OPPOSITE ENDS OF SAID INNER FRAME, SAIDENDLESS CLOTH BEING TRAINED AROUND SAID INNER FRAME, AND MEANS FORREMOVABLY SUPPORTING SAID SUCTION CHAMBER MEANS IN SAID INNER FRAME FORREMOVAL THEREFROM AND INSERTION THEREINTO THROUGH A SLIDE OF SAID INNERFRAME.